Laser liquid flow cell manifold system and method for assembly

Abstract

The flow cell system and method of the present invention for constructing and operating a light scattering test stand enables close reproducible tolerances to be achieved and automatically ensures the mutual alignment of the structures utilized to maintain stability. Pins and bosses are utilized to maintain alignment of the cell assembly with the read head. The flow cell assembly is held down in the read head independently of the stray light cover. The design of the present invention enables precision alignment reproducibility and ease of use.

What is claimed: 
     
       1. A flow cell assembly comprising: a first manifold section having an upper planar portion having a face end and a second end and a base portion defining a first optical opening;   a second manifold section having an upper planar portion having a face end and a second end and a base portion defining a second optical opening;   means for attaching said first manifold section to said second manifold section joining said face ends;   a base plate attachable to said base portions of said first and said second manifold sections;   a flow cell mountable between said base portions and between said upper planar portions and said base plate, and in conjunction with said first and second manifold sections establishing a fluid flow path from an opening defined by said first manifold section, through said flow cell, through and to an opening defined by said second manifold section, said first optical opening in communication with said second optical opening through a portion of said fluid flow path;   means for attaching said base plate to said base portion of said first and second manifold sections   optical sealing means, secured to said first and said second optical openings, for sealing said optical openings and facilitating the propagation of light through said optical openings.   
     
     
       2. The flow cell assembly recited in claim 1 wherein said first manifold section defines a pair of open bores extending longitudinally through said upper planar portion from said face end to said second end, and wherein said second manifold section defines a pair of threaded bores extending longitudinally into said face of said upper planar portion, and wherein said means for attaching said first manifold section to said second manifold section joining said face ends further comprises a pair of bolts extending through said open bores and threadably engaging said pair of threaded bores to secure said face end of said upper planar portion of said first manifold section to said face end of said upper planar portion of said second manifold section. 
     
     
       3. The flow cell assembly recited in claim 1 wherein said base portion of said first and second manifold sections each defines at least one threaded bore and wherein said base plate defines a plurality of apertures, with at least one of said plurality of apertures aligned with at least one said threaded bore of each of said base portions and wherein said means for attaching said base plate to said base portion of said first and second manifold sections are bolts threadably engagable with at least one said threaded bore of each of said base portions. 
     
     
       4. The flow cell assembly recited in claim 1 wherein said flow cell further comprises a glass structure having an upper planar surface parallel to a lower planar surface, a first flat end surface at one end of said flow cell adjacent to both upper and lower planar surfaces, a second flat end surface at the other end of said flow cell and adjacent to both upper and lower planar surfaces and parallel to said first flat end surface, and a first curved surface bridging said first and second flat end surfaces and adjacent so both said upper and lower planar surfaces, and a second curved surface bridging said first and second flat end surfaces and adjacent to both said upper and lower planar surfaces, and opposite said first curved surface, said flow cell defining a flow bore extending from said first flat end surface to said second flat end surface. 
     
     
       5. The flow cell assembly recited in claim 4 wherein said flow bore opens onto said first and said second flat end surfaces at their geometric center. 
     
     
       6. The flow cell assembly recited in claim 1 wherein said first and said second optical openings have an interior surface and wherein said optical sealing means further comprises: an o-ring seal sealingly engaging said interior surface of said optical opening;   an optical window abutting said o-ring seal; and   an optical window retainer abutting said optical window.   
     
     
       7. The flow cell assembly recited in claim 1 wherein said face end of said first manifold section carries a plurality of alignment pins and wherein said face end of said second manifold section carries a plurality of apertures, each one of said alignment pins fittable within an associated one of said apertures of said face end of said second manifold section. 
     
     
       8. The flow cell assembly recited in claim 1 wherein said base plate has a circular center section and a pair of rectangular ends, said circular center section approximately the same size as an abutting surface of said flow cell, and each of said pair of rectangular ends of approximately the same size as an abutting surface of said base portion. 
     
     
       9. A flow cell assembly comprising: a first manifold section having an upper planar portion having a face end and a second end and a base portion and defining an optical opening and defining a pair of open bores extending longitudinally through said upper planar portion from said face end to said second end;   a second manifold section having an upper planar portion having a face end and a second end and a base portion and defining an optical opening defining a pair of threaded bores extending longitudinally into said face of said upper planar portion;   a pair of bolts extending through said open bores and threadably engaging said pair of threaded bores to secure said face end of said upper planar portion of said first manifold section to said face end of said upper planar portion of said second manifold section;   a base plate attachable to said base portions of said first and said second manifold sections;   a flow cell mountable between said base portions and between said upper planar portions and said base plate, and defining a flow bore in optical alignment with said first and second optical openings of said base portions.   
     
     
       10. A supported flow cell assembly, including the flow cell assembly of claim 9 and wherein said upper planar portions of said first and said second manifold sections define a first plurality of apertures, and further comprising: an encapsulation support having an accommodation space for interfitting with and supporting said flow cell assembly, said encapsulation support having a second plurality of threaded apertures opening into said accommodation space and each of which align with an associated one of said first plurality of apertures of said upper planar portions of said first and said second manifold sections; and   a plurality of bolts extendable through said first plurality of apertures of said upper planar portions of said first and said second manifold sections and threadably engaged with said second plurality of threaded apertures in said encapsulation support.   
     
     
       11. The flow cell assembly recited in claim 9 wherein said upper planar portions of said first and said second manifold sections form a multi sided planar structure. 
     
     
       12. A supported flow cell assembly, including the flow cell assembly of claim 11 and wherein said upper planar portions of said first and said second manifold sections define a plurality of apertures, and further comprising: an encapsulation support having an accommodation space having vertical walls which extend generally parallel to the sides of said multi sided planar structure for interfitting with and supporting said flow cell assembly, said encapsulation support having a plurality of threaded apertures opening into said accommodation space and each of which align with an associated one of said apertures of said upper planar portions of said first and said second manifold sections, and having at least two contact pads along vertical walls for aligning said flow cell assembly;   a spring contact extending from at least one wall of said encapsulation support for urging said flow cell assembly against said contact pads; and   a plurality of bolts extendable through said apertures of said upper planar portions of said first and said second manifold sections and threadably engaged with said plurality of threaded apertures.   
     
     
       13. The flow cell assembly recited in claim 9 wherein said first and second manifold sections have underside surfaces defining an alignment structure, and wherein said flow cell has an upper surface having an alignment structure matable with said alignment structure of said first and second manifold sections. 
     
     
       14. A process of assembling a flow cell into a flow cell assembly comprising the steps of: orienting the first and second manifolds with their upper planar portions oriented downwardly and their base portions oriented upwardly;   aligning the flow bore of a flow cell with a flow bore in said first manifold and with a flow bore in said second manifold;   sandwiching a pair of o-rings on either side of said flow cell, each surrounding an opening of said flow bore of said flow cell;   compressibly joining said first and said second manifolds together to compress said o-rings against said flow cell and against said first and second manifolds; and   attaching a base plate to said base portions of said compressibly assembled said first and second manifolds to form a flow cell assembly.   
     
     
       15. The process of assembling a flow cell test stand, including the steps of assembling a flow cell assembly as recited in claim 14 and further comprising the steps of: placing said flow cell assembly into an accommodation space of an encapsulation support having laser ports in optical communication with said flow bore of said flow cell; and   attachably joining said flow cell assembly into said accommodation space of said encapsulation support.   
     
     
       16. A flow cell assembly for a liquid stream to be analyzed using a beam of light, the flow cell assembly comprising: a transparent flow cell including opposed end facets and an axial bore extending through the flow cell between the end facets,   first and second manifold sections, each section including a facet to mate against a facet of the transparent flow cell and a bore collinear with the bore of a mated flow cell, the first section being positioned at one end of the flow cell and the second section being positioned at the other, opposed end of the flow cell,   first alignment means to establish and hold the manifold sections together and in alignment such that their bores are collinear; and   second alignment means to establish and hold the flow cell against the manifolds and in alignment such that the flow cell bore is collinear with the manifold bores.   
     
     
       17. A flow cell assembly as set forth in claim 16 including means to seal the flow cell facets to the manifold section facets. 
     
     
       18. A flow cell assembly as set forth in claim 16 in which the flow cell has a cylindrically axial bore extending along a diameter of the flow cell and perpendicular to the opposed end facets. 
     
     
       19. A flow cell assembly as set forth in claim 16 in which the first alignment means includes mating pins and sockets in the manifold sections that engage one another. 
     
     
       20. A flow cell assembly as set forth in claim 19 in which the manifold sections abut one another when the flow cell assembly is held together by the alignment means, one of the manifold sections including projecting pins, the other of the manifold sections including sockets receiving the projecting pins. 
     
     
       21. A flow cell assembly as set forth in claim 16 and further comprising an encapsulation support having an accommodation space for interfitting with and supporting said flow cell assembly in which the first alignment means includes one or more pins protruding from the lower planar surfaces which mate with corresponding holes in the top surface of the accommodation space of the encapsulation support. 
     
     
       22. A flow cell assembly as set forth in claim 16 and further comprising an encapsulation support having an accommodation space for interfitting with and supporting said flow cell assembly in which the first alignment means includes two or more vertical surfaces in the accommodation space of the encapsulation support serving as pads which guide corresponding vertical surfaces of the planar sections of the cell assembly manifolds. 
     
     
       23. A flow cell assembly as set forth in claim 16 in which the second alignment means includes a step in a horizontal surface of the flow cell parallel to the bore which mates with a corresponding step in a horizontal surface of at least one of the manifolds. 
     
     
       24. A flow cell for use in a flow cell assembly to contain a liquid stream to be analyzed using a beam of light, the flow cell comprising: a transparent substantially cylindrical body,   an bore through a diameter of the substantially cylindrical body,   a planar end facet at each end of the body, the bore extending between and terminating at the planar end facets, and   a window in the side of the body through which liquid flowing in the bore may be viewed.   
     
     
       25. A flow cell for use in a flow cell assembly as set forth in claim 24 wherein said transparent substantially cylindrical body further comprises flat, parallel upper and lower faces. 
     
     
       26. A flow cell for use in a flow cell assembly as set forth in claim 25 wherein said transparent substantially cylindrical body further comprises a circular, cylindrical window. 
     
     
       27. A flow cell for use in a flow cell assembly as set forth in claim 26 including a pair of windows, each located a short distance away from said end facets.